ostree/src
Colin Walters 5af403be0c Support mounting /sysroot (and /boot) read-only
We want to support extending the read-only state to cover `/sysroot`
and `/boot`, since conceptually all of the data there should only
be written via libostree.  Or at least for `/boot` should *mostly*
just be written by ostree.

This change needs to be opt-in though to avoid breaking anyone.

Add a `sysroot/readonly` key to the repository config which instructs
`ostree-remount.service` to ensure `/sysroot` is read-only.  This
requires a bit of a dance because `/sysroot` is actually the same
filesystem as `/`; so we make `/etc` a writable bind mount in this case.

We also need to handle `/var` in the "OSTree default" case of a bind
mount; the systemd generator now looks at the writability state of
`/sysroot` and uses that to determine whether it should have the
`var.mount` unit happen before or after `ostree-remount.service.`

Also add an API to instruct the libostree shared library
that the caller has created a new mount namespace.  This way
we can freely remount read-write.

This approach extends upon in a much better way previous work
we did to support remounting `/boot` read-write.

Closes: https://github.com/ostreedev/ostree/issues/1265
2019-12-11 15:33:57 +00:00
..
boot Support mounting /sysroot (and /boot) read-only 2019-12-11 15:33:57 +00:00
libostree Support mounting /sysroot (and /boot) read-only 2019-12-11 15:33:57 +00:00
libotutil lib/keyfile: Treat "group not found" the same as "key not found" 2019-11-07 21:15:41 +00:00
ostree Support mounting /sysroot (and /boot) read-only 2019-12-11 15:33:57 +00:00
rofiles-fuse rofiles-fuse: Improve error message for failure to open root 2018-10-12 14:11:10 +00:00
switchroot Support mounting /sysroot (and /boot) read-only 2019-12-11 15:33:57 +00:00